void setup() { // Start serial communication on both Serial (for debug) and Serial1 (for UART) Serial.begin(9600); // Serial monitor Serial1.begin(9600); // UART communication with Arduino Uno } void loop() { // Check if data is available on Serial1 (connected to Arduino) if (Serial1.available()) { // Read data from Serial1 and send it to Serial monitor String data = Serial1.readString(); Serial.println("Received: " + data); } }